Voltage Comparator circuit:-   A fixed reference voltage Vref  is applied to the (-) input, and the other time – varying signal voltage Vin is applied to the (+) input; Because of this arrangement, the circuit is called the non-inverting comparator.  Depending upon the levels of Vin and Vref the circuit produces output.  In short, the comparator is a type of analog-to-digital converter.

At any given time the output waveform shows whether Vin is greater or less than Vref.  The comparator is sometimes also called a voltage-level detector because, for a  desired value of Vref, the voltage level of the input Vin can be detected.

• A fixed reference voltage Vref is applied to the (-) input, and to the other input a varying voltage Vin.
• Vary the input voltage above and below the Vref  and note down the output at pin 6 of 741 IC.
• Observe that, when Vin less than Vref, the output voltage is -Vsat ( @ – VEE)
•  when Vin is greater than Vref­, the output voltage is +Vsat (@+VCC).

Comparator Calculation:

• If Vin < Vref, Vo = -Vsat @ – VEE
• Vin > Vref, Vo = +Vsat = +VCC.

Readings;

 Vin V Ref=v V = o/p 3 .75 +10 6 7.2 -10.5